Centrifugal pipe mold



Feb. 24, 1925.

c. E. W ILDER CENTRIFUGAL'PIPE MOLD Filed Oct. 2.5, 1923 2 SheetsPSheet1 VAk Feb. 24, 1925. c. E. WILDER CENTRIFUGAL PIPE HULD Filed Oct. 25,1925 2 Sheets-Sheet? Patented Feb. 24, 1925.

UNITED STATES PATENT OFFICE.

crimson n. wnamn, or mvnm, rnnnsnvanm.

CENTBIFUGAL PIPE HOLD.

Application filed octol er as, 192:. Serial Ira-erases.

To all whom it may concern:

Be it known that I, CLINTON E. Wrronn,

a citizen of the United States, residing at Irvine, in the county ofWarren and State of Pennsylvania, have invented certain new and usefulImprovements in Centrifugal- Pipe Molds; and I do hereby, declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the artto'wliich it appertains tomake and use the same, reference being had to the accompanying drawings,and to'the letters of reference marked thereon, forming part of thisspecification.

This invention relates to improvements in the construction of mold tubesfor centrifugal casting machines, in which machines the mold tube isrotated at a high rate of speed while a stream of molten metal isintroduced therein in asuitable manner. v

Herctofore it has been the practice to construct the mold tubes forcentrifugal casting machines of suflicient wall thickness to ensure themold tube retaining accurate align- .ment which necessitatespa wallsubstantiallyone and one-half inches thick. This mold tube is placed inan enclosing-jacket spaced therefrom, and mounted in suitable bearings,

and provided with mechanism adapted t9 cause the mold tube to rotaterapidly within said jacket, and there is provided a means to. circulatewater in the space between said acket and mold tube to keep the moldtube which has been cooled sufliciently to shrink V cool, as shown in U.S. patent to De Lavaud No. 1,398,008.

I have found from practice that with the thick walled mold tubeconsiderable time is required for the thick wall of mold tube to cool,after being heated by the moltenmetal, owing to the resistance of thethick, heated, mold tubeto the'transference of cold from the waterjacket to the layer of hot metal loose from the mold tube and bewithdrawn therefrom.

come the difliculties incident to'the use of a thick walled mold tubeina casting machine. I overcome these difiiculties by providing acomparatively thin,-say one half of aning radially therefrom "studsadapted to en- 1 gage the interior surface of said thick walled moldtube to support said thin walled liner, and between said elastic metalbands the space between the liner and the thick mold est diameter, andflows therefrom backintofsaid jacket through holesin the wall of thethick mold tube at its greatest diameter, thus causing a continuously.moderate longitudinal circulation of cooling fluid through the spacebetween said tubes without causing the liner to become checked orotherwise injured, the cooling medium in the space becoming sufficientlyheated to prevent injury to the cast metal, and yet preventing the thinliner from becoming injured. The thin wall: of the liner presents solittle-resistance to the transference of cold from the cooling medi, umto the cast metal, that it is quickly cooled sufficiently to be removedfrom the liner.

These and. other features of this invention will be hereinafter setforth and pointed out, and are illustrated in the accompanying drawingsin which:

Figure 1 is a longitudinal section of a mold tube and'liner therein,according to my invention. I

" Figure 2 is a transverse section thereof on the line 22- in Fig. 1. w

Figure 3 is a transverse section of the same on the line 3-3 inFig. 1.

Figure tie a transvers'e'section of the sam on the line 4+4 in Fig. 1 1

In these drawings A indicates the ordinary thick mold tube as ordinarilyused 4 4 a centrifugal casting machine, and as or- The object of thisinvention is to over-' dinarily used in a machine of the De Lavaud itsinterior, while in this invention the thick tube- A serves only tosupport, in true alignment, the comparatively thin lining tube B,-

-which in reality is. the mold tube of the structure.

'- The thick mold tube A. is provided with series of holes a at thesmall diameter of the tube, as at- .the cross-seetionlal- (see Fig. 4)Said holes are at an angl through the wall of the mold tube A, so thatwhen the tube revolves in the direction of the arrow in Fig. 4, theytend to scoop in water from the water jacket, (not shown) of themachine, in which the tuber-evolves. There are preferably several'seriesof these holes a along the length of the tube, while at the largestdiameter of the mold tube A is a series of holes a at the cross sectionline 2-2 in Fig. 1, see Fig. 2, which are inclined backward from thedirection of revolution of the tube A so that they will not scoop inwater from the water jacket (not shown) and being at a greater diametertend to throw the water out of the holes a and thus tube A, so as toallow.for the expansion of the tube B during the pouring of the moltenmetal thereinto. Thus it will be seen that the thin lining tube B. willbe perfectly supported by the thick outside tube A,

' and prevented from becoming out of alignheat;

ment. I

The space between the tubes A and B between t e elastic metallic rings Cis filled with'coiled wire D, the several coils D being interlaced asshown in Figs, 2 and 4,

so that they will form a band of coiled wire around the tube B betweenthe rings C. The diameter of the coils D is equal to the width of thespace between the tube A and the tube B.

Into the several coils D I place material capable of absorbing water andresisting I have found that asbestos rope is well adapted for thispurpose. This asbestos material fills the interior of the wire coils,but leaves spaces (1 between the wire coils on the walls of the tubes Aand B, andbe; tween the coils D through which water can circulatelongitudinally of the tube A. These wire coils D, thus filled with aporous material D acts to keep the thin tube'B in alignment between therings C, and serves to retard the longitudinal flow of water through thespace between said tubes. so that the water becomes sufiiciently hotenough to prevent over chilling of the-casting, and at the same timeprevents injuring the tube B. The difference in temperature between thewater in the space between the tubes A. and-B will be readilytransferred through the thin tube B to the layer of hot metal thereon tocause it to cool sufficiently to shrink away from the mold tube B sothat it can easily be withdrawn therefrom.

The outer tube A is provided with an annular shoulder E against whichthe outturned flange E on the tube B engages, and from 1 the shoulder Escrew threads F are provided in the outer tube, which engage threads ona rin G which screw into the end of the tube A and force the flange Esecurely against the annular shoulder E.

At the opposite end of the tube A is an inturned annular flange Hagainst which the coils -D and rope filler D abut, while the inner tubeB extends through the flange H and through a gland-ring H which pressesagainst suitable packing in to seal the joint between the tube B andflange H. Secured to the outer tube A are tap bolts J upon which a ringK is placed which is adapted to engage'the end of the tube B. and on thetap bolts springs J and nuts J 2 are placed so that the springs J pressagainst and force the ring K against the tube B with a yielding pressureso as to compensate for the longitudinal expansion of the inner tube B.1

In use, this outer tube A and lining tube B are inserted into a moldingmachine of the type shown and described in U. S.

Patent No. 1,398,008, hereinbefore-referred to, in the usual manner andthe water jacket therein filled with water in the usual manner, so thatwhen the mold tubes herein des'cfibed are rotated, water from the waterjacket enters into the space between the outer thick tube A and theinner liner tube B' through the holes a in the wall of the tube A andsaturates the asbestos filler in the coiled wire centering supports D,and is caused toqlongitudinally circulate thereabout and therethrough byreason of the difierence in diameter of the tube A where the intakeholes a and the outlet holes a pierce the wall of said tube, so that theoutside of the thin mold tube B is at all times surrounded by a hotmoist layer of heat proof material with sufficient circulation to carryoff the burning heat of the molten metal, and thereby prevent the'burning'of the tube B, so that the same will not become checked on itsinner surface, and will not become sufliciently chilled to injure thesurface of the cast metal. The thin wall of the tube B, offers little,if any. resistance to the transference of heat from the cast' metal tocirculating cooling water inthe space between the two tubes A and B, andwhich is carried ofi thereby. 7

As the pouring spout recedes, and the molten metal is laid upon theinner surface of the rotating mold tube B, always upon a portion whichhas been cooled by the slowlycirculating cooling fluid, said.

fluidbecoming thereby heated as it travels forward over that portion ofthe mold tube upon which the hot metal has been deposited, so that whilethe incoming cooling fluid nmintains the succeeding portion of the moldtube in a cool condition to receive the metal deposited thereon, thecooling water at the point receiving the hot metal becoming sufficientlyheated to cause the molten metal to cool slowly so as not to.

duced, so that the initial diameter of the cast metal is correspondinglyreduced, so that the contraction of the cast metal as it hardens .isrelatively greater than the contraction of the tube B, so that an airspace progressively forms between the cast metal and the tube B, whichspace progresses longitudinally until the casting is' finished.

During this progressive casting operation the cooling medium between thetubes A and B becomes heated sufliciently to prevent the contraction ofthe tube B, but still retains a sufficient difference in temperature tocarry oil the heat from the cast metal to cause the required amount ofcontraction to enable it to be easily withdrawn from the mold tube.

Because the mold tube B, being comparatively thin, is easily kept coolthe machine casting toshrink sufliciently to be withdralwn, or for anoverheated'mo-ld tube to coo Having thus described my improved moldingtube for I centrifugal casting machines, so that others will be able toutilize the same, I do not desireto be limited to the exact constructionthereof herein shown and described, as it is evident that-manymodifications can *be made therein without departing from thescope of myinvention,v

therefore what I claim as new and desire to secure by Letters Patent is:

-1. A mold tube having a comparatively thin wall, another tube having athick wall enclosing said mold tube and spaced therefrom, elastic meanssurrounding said mold tube and contacting with the inner surface of saidthick' outer tube and adapted to maintain all portions of said mold tubeconcentriowith the inner wall of said thick;

outer'tube, and means to 'causea longitudinal circulation-of waterbetween said from, elastic'means surrounding said moldtube andcontacting with the inner surface of said thick outer tube, and adaptedto maintain all portions of said mold tube concentric with the innerwall of said thickouter tube, and means to cause a longitudinalcirculation o-f water between said tubes, asbestos material fillingbetween elastic means to retard said circulation.

3. In a mold tube having a comparatively thin wall, another tube havinga comparatively thick wall enclosing said mold tube and spacedtherefrom, a series of corrugated metallic rings surrounding said moldtube, spaced at intervals, radial studs formed on said rings and adaptedto engage the inner surface of said outer tube, means to cause a tivelythick wall enclosing said mold tube and spaced therefrom, longitudinallyinterlaced coiled wires engaging the outer sur face of the thin moldtube and the inner surface of the thick outer tube and adapted to maintain ,themold tube longitudinally concentric with said outer tube,asbestos material extending through each of said wire coils, and meansto cause water to longitudinally circulate through the annular spacebetween said tubes.

5. In a. moldtube having a comparatively thin wall, another tube havinga compara- .tively thick wall enclosingsaid thin tube, does not have tostandidle to permit the a means to cause water to longitudinallycirculate through the annular space between said tubes, -and means toretard said circulation. I

, 6; Ina mold apparatus, an inner mold tube having a thin wall, an outertube enclosing said mold tube and adapted to support the same,- metallicrings placed at intervals on said innertube and adapted to engage theinner surface of said outer tube to concentrically support said moldtube within said outer tube, inte-rlaced coiled wire around said moldtube between said corrugated rings of a diameterto engage the outersurface of the mold-tube and the inner surface of the thick "outer tubeadapted-to concentrically support said,mold"t1 1be within said outeraplurality of corrugated tube between-said corrugated metallic rings,

and asbestos ropes inserted longitudinally through said interlaced wirecoils.

In testimony whereof I aflix my signature.

cnmron E, WILDER.

